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Registered in England and Wales under Company Registration No. 3798903 From: David Howells Subject: [PATCH 02/24] CRED: Split the task security data and move part of it into struct cred To: viro@ftp.linux.org.uk, hch@infradead.org, Trond.Myklebust@netapp.com, sds@tycho.nsa.gov, casey@schaufler-ca.com Cc: linux-kernel@vger.kernel.org, selinux@tycho.nsa.gov, linux-security-module@vger.kernel.org, dhowells@redhat.com Date: Wed, 26 Sep 2007 15:21:10 +0100 Message-ID: <20070926142110.2656.78572.stgit@warthog.procyon.org.uk> In-Reply-To: <20070926142059.2656.27100.stgit@warthog.procyon.org.uk> References: <20070926142059.2656.27100.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.13 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 52910 Lines: 1668 Move into the cred struct the part of the task security data that defines how a task acts upon an object. The part that defines how something acts upon a task remains attached to the task. For SELinux this requires some of task_security_struct to be split off into cred_security_struct which is then attached to struct cred. Note that the contents of cred_security_struct may not be changed without the generation of a new struct cred. The split is as follows: (*) create_sid, keycreate_sid and sockcreate_sid just move across. (*) sid is split into victim_sid - which remains - and action_sid - which migrates. (*) osid, exec_sid and ptrace_sid remain. victim_sid is the SID used to govern actions upon the task. action_sid is used to govern actions made by the task. When accessing the cred_security_struct of another process, RCU read procedures must be observed. Signed-off-by: David Howells --- include/linux/cred.h | 1 include/linux/security.h | 33 ++ kernel/cred.c | 7 + security/dummy.c | 11 + security/selinux/exports.c | 6 security/selinux/hooks.c | 497 +++++++++++++++++++++++-------------- security/selinux/include/objsec.h | 16 + security/selinux/selinuxfs.c | 8 - security/selinux/xfrm.c | 6 9 files changed, 379 insertions(+), 206 deletions(-) diff --git a/include/linux/cred.h b/include/linux/cred.h index 0cc4400..7e35b2f 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -26,6 +26,7 @@ struct cred { gid_t gid; /* fsgid as was */ struct rcu_head exterminate; /* cred destroyer */ struct group_info *group_info; + void *security; /* caches for references to the three task keyrings * - note that key_ref_t isn't typedef'd at this point, hence the odd diff --git a/include/linux/security.h b/include/linux/security.h index 1a15526..74cc204 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -504,6 +504,17 @@ struct request_sock; * @file contains the file structure being received. * Return 0 if permission is granted. * + * Security hooks for credential structure operations. + * + * @cred_dup: + * Duplicate the credentials onto a duplicated cred structure. + * @cred points to the credentials structure. cred->security points to the + * security struct that was attached to the original cred struct, but it + * lacks a reference for the duplication if reference counting is needed. + * @cred_destroy: + * Destroy the credentials attached to a cred structure. + * @cred points to the credentials structure that is to be destroyed. + * * Security hooks for task operations. * * @task_create: @@ -1257,6 +1268,9 @@ struct security_operations { struct fown_struct * fown, int sig); int (*file_receive) (struct file * file); + int (*cred_dup)(struct cred *cred); + void (*cred_destroy)(struct cred *cred); + int (*task_create) (unsigned long clone_flags); int (*task_alloc_security) (struct task_struct * p); void (*task_free_security) (struct task_struct * p); @@ -1864,6 +1878,16 @@ static inline int security_file_receive (struct file *file) return security_ops->file_receive (file); } +static inline int security_cred_dup(struct cred *cred) +{ + return security_ops->cred_dup(cred); +} + +static inline void security_cred_destroy(struct cred *cred) +{ + return security_ops->cred_destroy(cred); +} + static inline int security_task_create (unsigned long clone_flags) { return security_ops->task_create (clone_flags); @@ -2546,6 +2570,15 @@ static inline int security_file_receive (struct file *file) return 0; } +static inline int security_cred_dup(struct cred *cred) +{ + return 0; +} + +static inline void security_cred_destroy(struct cred *cred) +{ +} + static inline int security_task_create (unsigned long clone_flags) { return 0; diff --git a/kernel/cred.c b/kernel/cred.c index 5b56b2b..9868eef 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -94,6 +94,12 @@ struct cred *dup_cred(const struct cred *pcred) if (likely(cred)) { *cred = *pcred; atomic_set(&cred->usage, 1); + + if (security_cred_dup(cred) < 0) { + kfree(cred); + return NULL; + } + get_group_info(cred->group_info); #ifdef CONFIG_KEYS key_get(key_ref_to_ptr(cred->session_keyring)); @@ -113,6 +119,7 @@ static void put_cred_rcu(struct rcu_head *rcu) { struct cred *cred = container_of(rcu, struct cred, exterminate); + security_cred_destroy(cred); put_group_info(cred->group_info); key_ref_put(cred->session_keyring); key_ref_put(cred->process_keyring); diff --git a/security/dummy.c b/security/dummy.c index 62de89c..f535cc6 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -468,6 +468,15 @@ static int dummy_file_receive (struct file *file) return 0; } +static int dummy_cred_dup(struct cred *cred) +{ + return 0; +} + +static void dummy_cred_destroy(struct cred *cred) +{ +} + static int dummy_task_create (unsigned long clone_flags) { return 0; @@ -1038,6 +1047,8 @@ void security_fixup_ops (struct security_operations *ops) set_to_dummy_if_null(ops, file_set_fowner); set_to_dummy_if_null(ops, file_send_sigiotask); set_to_dummy_if_null(ops, file_receive); + set_to_dummy_if_null(ops, cred_dup); + set_to_dummy_if_null(ops, cred_destroy); set_to_dummy_if_null(ops, task_create); set_to_dummy_if_null(ops, task_alloc_security); set_to_dummy_if_null(ops, task_free_security); diff --git a/security/selinux/exports.c b/security/selinux/exports.c index b6f9694..29cb87a 100644 --- a/security/selinux/exports.c +++ b/security/selinux/exports.c @@ -57,7 +57,7 @@ void selinux_get_task_sid(struct task_struct *tsk, u32 *sid) { if (selinux_enabled) { struct task_security_struct *tsec = tsk->security; - *sid = tsec->sid; + *sid = tsec->victim_sid; return; } *sid = 0; @@ -77,9 +77,9 @@ EXPORT_SYMBOL_GPL(selinux_string_to_sid); int selinux_relabel_packet_permission(u32 sid) { if (selinux_enabled) { - struct task_security_struct *tsec = current->security; + struct cred_security_struct *csec = current->cred->security; - return avc_has_perm(tsec->sid, sid, SECCLASS_PACKET, + return avc_has_perm(csec->action_sid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL); } return 0; diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 0753b20..4e72dbb 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -162,7 +162,8 @@ static int task_alloc_security(struct task_struct *task) return -ENOMEM; tsec->task = task; - tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED; + tsec->osid = tsec->victim_sid = tsec->ptrace_sid = + SECINITSID_UNLABELED; task->security = tsec; return 0; @@ -177,7 +178,7 @@ static void task_free_security(struct task_struct *task) static int inode_alloc_security(struct inode *inode) { - struct task_security_struct *tsec = current->security; + struct cred_security_struct *csec = current->cred->security; struct inode_security_struct *isec; isec = kmem_cache_zalloc(sel_inode_cache, GFP_KERNEL); @@ -189,7 +190,7 @@ static int inode_alloc_security(struct inode *inode) isec->inode = inode; isec->sid = SECINITSID_UNLABELED; isec->sclass = SECCLASS_FILE; - isec->task_sid = tsec->sid; + isec->task_sid = csec->action_sid; inode->i_security = isec; return 0; @@ -211,7 +212,7 @@ static void inode_free_security(struct inode *inode) static int file_alloc_security(struct file *file) { - struct task_security_struct *tsec = current->security; + struct cred_security_struct *csec = current->cred->security; struct file_security_struct *fsec; fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); @@ -219,8 +220,8 @@ static int file_alloc_security(struct file *file) return -ENOMEM; fsec->file = file; - fsec->sid = tsec->sid; - fsec->fown_sid = tsec->sid; + fsec->sid = csec->action_sid; + fsec->fown_sid = csec->action_sid; file->f_security = fsec; return 0; @@ -335,26 +336,26 @@ static match_table_t tokens = { static int may_context_mount_sb_relabel(u32 sid, struct superblock_security_struct *sbsec, - struct task_security_struct *tsec) + struct cred_security_struct *csec) { int rc; - rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, + rc = avc_has_perm(csec->action_sid, sbsec->sid, SECCLASS_FILESYSTEM, FILESYSTEM__RELABELFROM, NULL); if (rc) return rc; - rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, + rc = avc_has_perm(csec->action_sid, sid, SECCLASS_FILESYSTEM, FILESYSTEM__RELABELTO, NULL); return rc; } static int may_context_mount_inode_relabel(u32 sid, struct superblock_security_struct *sbsec, - struct task_security_struct *tsec) + struct cred_security_struct *csec) { int rc; - rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, + rc = avc_has_perm(csec->action_sid, sbsec->sid, SECCLASS_FILESYSTEM, FILESYSTEM__RELABELFROM, NULL); if (rc) return rc; @@ -371,7 +372,7 @@ static int try_context_mount(struct super_block *sb, void *data) const char *name; u32 sid; int alloc = 0, rc = 0, seen = 0; - struct task_security_struct *tsec = current->security; + struct cred_security_struct *csec = current->cred->security; struct superblock_security_struct *sbsec = sb->s_security; if (!data) @@ -503,7 +504,7 @@ static int try_context_mount(struct super_block *sb, void *data) goto out_free; } - rc = may_context_mount_sb_relabel(sid, sbsec, tsec); + rc = may_context_mount_sb_relabel(sid, sbsec, csec); if (rc) goto out_free; @@ -525,12 +526,12 @@ static int try_context_mount(struct super_block *sb, void *data) } if (!fscontext) { - rc = may_context_mount_sb_relabel(sid, sbsec, tsec); + rc = may_context_mount_sb_relabel(sid, sbsec, csec); if (rc) goto out_free; sbsec->sid = sid; } else { - rc = may_context_mount_inode_relabel(sid, sbsec, tsec); + rc = may_context_mount_inode_relabel(sid, sbsec, csec); if (rc) goto out_free; } @@ -550,7 +551,7 @@ static int try_context_mount(struct super_block *sb, void *data) goto out_free; } - rc = may_context_mount_inode_relabel(sid, sbsec, tsec); + rc = may_context_mount_inode_relabel(sid, sbsec, csec); if (rc) goto out_free; @@ -570,7 +571,7 @@ static int try_context_mount(struct super_block *sb, void *data) if (sid == sbsec->def_sid) goto out_free; - rc = may_context_mount_inode_relabel(sid, sbsec, tsec); + rc = may_context_mount_inode_relabel(sid, sbsec, csec); if (rc) goto out_free; @@ -1025,15 +1026,22 @@ static inline u32 signal_to_av(int sig) /* Check permission betweeen a pair of tasks, e.g. signal checks, fork check, ptrace check, etc. */ -static int task_has_perm(struct task_struct *tsk1, - struct task_struct *tsk2, +static int task_has_perm(struct task_struct *actor, + struct task_struct *victim, u32 perms) { - struct task_security_struct *tsec1, *tsec2; + struct cred_security_struct *csec; + struct task_security_struct *tsec; + u32 action_sid; + + /* the actor may not be the current task */ + rcu_read_lock(); + csec = task_cred(actor)->security; + action_sid = csec->action_sid; + rcu_read_unlock(); - tsec1 = tsk1->security; - tsec2 = tsk2->security; - return avc_has_perm(tsec1->sid, tsec2->sid, + tsec = victim->security; + return avc_has_perm(action_sid, tsec->victim_sid, SECCLASS_PROCESS, perms, NULL); } @@ -1041,16 +1049,16 @@ static int task_has_perm(struct task_struct *tsk1, static int task_has_capability(struct task_struct *tsk, int cap) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct avc_audit_data ad; - tsec = tsk->security; + csec = tsk->cred->security; AVC_AUDIT_DATA_INIT(&ad,CAP); ad.tsk = tsk; ad.u.cap = cap; - return avc_has_perm(tsec->sid, tsec->sid, + return avc_has_perm(csec->action_sid, csec->action_sid, SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad); } @@ -1058,11 +1066,11 @@ static int task_has_capability(struct task_struct *tsk, static int task_has_system(struct task_struct *tsk, u32 perms) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; - tsec = tsk->security; + csec = tsk->cred->security; - return avc_has_perm(tsec->sid, SECINITSID_KERNEL, + return avc_has_perm(csec->action_sid, SECINITSID_KERNEL, SECCLASS_SYSTEM, perms, NULL); } @@ -1074,14 +1082,14 @@ static int inode_has_perm(struct task_struct *tsk, u32 perms, struct avc_audit_data *adp) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct inode_security_struct *isec; struct avc_audit_data ad; if (unlikely (IS_PRIVATE (inode))) return 0; - tsec = tsk->security; + csec = tsk->cred->security; isec = inode->i_security; if (!adp) { @@ -1090,7 +1098,8 @@ static int inode_has_perm(struct task_struct *tsk, ad.u.fs.inode = inode; } - return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp); + return avc_has_perm(csec->action_sid, isec->sid, isec->sclass, perms, + adp); } /* Same as inode_has_perm, but pass explicit audit data containing @@ -1121,7 +1130,7 @@ static int file_has_perm(struct task_struct *tsk, struct file *file, u32 av) { - struct task_security_struct *tsec = tsk->security; + struct cred_security_struct *csec = tsk->cred->security; struct file_security_struct *fsec = file->f_security; struct vfsmount *mnt = file->f_path.mnt; struct dentry *dentry = file->f_path.dentry; @@ -1133,8 +1142,8 @@ static int file_has_perm(struct task_struct *tsk, ad.u.fs.mnt = mnt; ad.u.fs.dentry = dentry; - if (tsec->sid != fsec->sid) { - rc = avc_has_perm(tsec->sid, fsec->sid, + if (csec->action_sid != fsec->sid) { + rc = avc_has_perm(csec->action_sid, fsec->sid, SECCLASS_FD, FD__USE, &ad); @@ -1154,36 +1163,36 @@ static int may_create(struct inode *dir, struct dentry *dentry, u16 tclass) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct inode_security_struct *dsec; struct superblock_security_struct *sbsec; u32 newsid; struct avc_audit_data ad; int rc; - tsec = current->security; + csec = current->cred->security; dsec = dir->i_security; sbsec = dir->i_sb->s_security; AVC_AUDIT_DATA_INIT(&ad, FS); ad.u.fs.dentry = dentry; - rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, + rc = avc_has_perm(csec->action_sid, dsec->sid, SECCLASS_DIR, DIR__ADD_NAME | DIR__SEARCH, &ad); if (rc) return rc; - if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { - newsid = tsec->create_sid; + if (csec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { + newsid = csec->create_sid; } else { - rc = security_transition_sid(tsec->sid, dsec->sid, tclass, - &newsid); + rc = security_transition_sid(csec->action_sid, dsec->sid, + tclass, &newsid); if (rc) return rc; } - rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad); + rc = avc_has_perm(csec->action_sid, newsid, tclass, FILE__CREATE, &ad); if (rc) return rc; @@ -1196,11 +1205,12 @@ static int may_create(struct inode *dir, static int may_create_key(u32 ksid, struct task_struct *ctx) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; - tsec = ctx->security; + csec = ctx->cred->security; - return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); + return avc_has_perm(csec->action_sid, ksid, SECCLASS_KEY, KEY__CREATE, + NULL); } #define MAY_LINK 0 @@ -1213,13 +1223,13 @@ static int may_link(struct inode *dir, int kind) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct inode_security_struct *dsec, *isec; struct avc_audit_data ad; u32 av; int rc; - tsec = current->security; + csec = current->cred->security; dsec = dir->i_security; isec = dentry->d_inode->i_security; @@ -1228,7 +1238,7 @@ static int may_link(struct inode *dir, av = DIR__SEARCH; av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); - rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad); + rc = avc_has_perm(csec->action_sid, dsec->sid, SECCLASS_DIR, av, &ad); if (rc) return rc; @@ -1247,7 +1257,7 @@ static int may_link(struct inode *dir, return 0; } - rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad); + rc = avc_has_perm(csec->action_sid, isec->sid, isec->sclass, av, &ad); return rc; } @@ -1256,14 +1266,14 @@ static inline int may_rename(struct inode *old_dir, struct inode *new_dir, struct dentry *new_dentry) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; struct avc_audit_data ad; u32 av; int old_is_dir, new_is_dir; int rc; - tsec = current->security; + csec = current->cred->security; old_dsec = old_dir->i_security; old_isec = old_dentry->d_inode->i_security; old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); @@ -1272,16 +1282,16 @@ static inline int may_rename(struct inode *old_dir, AVC_AUDIT_DATA_INIT(&ad, FS); ad.u.fs.dentry = old_dentry; - rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR, + rc = avc_has_perm(csec->action_sid, old_dsec->sid, SECCLASS_DIR, DIR__REMOVE_NAME | DIR__SEARCH, &ad); if (rc) return rc; - rc = avc_has_perm(tsec->sid, old_isec->sid, + rc = avc_has_perm(csec->action_sid, old_isec->sid, old_isec->sclass, FILE__RENAME, &ad); if (rc) return rc; if (old_is_dir && new_dir != old_dir) { - rc = avc_has_perm(tsec->sid, old_isec->sid, + rc = avc_has_perm(csec->action_sid, old_isec->sid, old_isec->sclass, DIR__REPARENT, &ad); if (rc) return rc; @@ -1291,15 +1301,17 @@ static inline int may_rename(struct inode *old_dir, av = DIR__ADD_NAME | DIR__SEARCH; if (new_dentry->d_inode) av |= DIR__REMOVE_NAME; - rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad); + rc = avc_has_perm(csec->action_sid, new_dsec->sid, SECCLASS_DIR, av, + &ad); if (rc) return rc; if (new_dentry->d_inode) { new_isec = new_dentry->d_inode->i_security; new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); - rc = avc_has_perm(tsec->sid, new_isec->sid, + rc = avc_has_perm(csec->action_sid, new_isec->sid, new_isec->sclass, - (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); + (new_is_dir ? DIR__RMDIR : FILE__UNLINK), + &ad); if (rc) return rc; } @@ -1313,12 +1325,12 @@ static int superblock_has_perm(struct task_struct *tsk, u32 perms, struct avc_audit_data *ad) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct superblock_security_struct *sbsec; - tsec = tsk->security; + csec = tsk->cred->security; sbsec = sb->s_security; - return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, + return avc_has_perm(csec->action_sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); } @@ -1371,7 +1383,7 @@ static inline u32 file_to_av(struct file *file) static int selinux_ptrace(struct task_struct *parent, struct task_struct *child) { - struct task_security_struct *psec = parent->security; + struct cred_security_struct *psec; struct task_security_struct *csec = child->security; int rc; @@ -1381,8 +1393,12 @@ static int selinux_ptrace(struct task_struct *parent, struct task_struct *child) rc = task_has_perm(parent, child, PROCESS__PTRACE); /* Save the SID of the tracing process for later use in apply_creds. */ - if (!(child->ptrace & PT_PTRACED) && !rc) - csec->ptrace_sid = psec->sid; + if (!(child->ptrace & PT_PTRACED) && !rc) { + rcu_read_lock(); + psec = task_cred(parent)->security; + csec->ptrace_sid = psec->action_sid; + rcu_read_unlock(); + } return rc; } @@ -1472,7 +1488,7 @@ static int selinux_sysctl(ctl_table *table, int op) { int error = 0; u32 av; - struct task_security_struct *tsec; + struct cred_security_struct *csec; u32 tsid; int rc; @@ -1480,7 +1496,7 @@ static int selinux_sysctl(ctl_table *table, int op) if (rc) return rc; - tsec = current->security; + csec = current->cred->security; rc = selinux_sysctl_get_sid(table, (op == 0001) ? SECCLASS_DIR : SECCLASS_FILE, &tsid); @@ -1492,7 +1508,7 @@ static int selinux_sysctl(ctl_table *table, int op) /* The op values are "defined" in sysctl.c, thereby creating * a bad coupling between this module and sysctl.c */ if(op == 001) { - error = avc_has_perm(tsec->sid, tsid, + error = avc_has_perm(csec->action_sid, tsid, SECCLASS_DIR, DIR__SEARCH, NULL); } else { av = 0; @@ -1501,7 +1517,7 @@ static int selinux_sysctl(ctl_table *table, int op) if (op & 002) av |= FILE__WRITE; if (av) - error = avc_has_perm(tsec->sid, tsid, + error = avc_has_perm(csec->action_sid, tsid, SECCLASS_FILE, av, NULL); } @@ -1589,11 +1605,11 @@ static int selinux_syslog(int type) static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) { int rc, cap_sys_admin = 0; - struct task_security_struct *tsec = current->security; + struct cred_security_struct *csec = current->cred->security; rc = secondary_ops->capable(current, CAP_SYS_ADMIN); if (rc == 0) - rc = avc_has_perm_noaudit(tsec->sid, tsec->sid, + rc = avc_has_perm_noaudit(csec->action_sid, csec->action_sid, SECCLASS_CAPABILITY, CAP_TO_MASK(CAP_SYS_ADMIN), 0, @@ -1626,6 +1642,7 @@ static int selinux_bprm_alloc_security(struct linux_binprm *bprm) static int selinux_bprm_set_security(struct linux_binprm *bprm) { struct task_security_struct *tsec; + struct cred_security_struct *csec; struct inode *inode = bprm->file->f_path.dentry->d_inode; struct inode_security_struct *isec; struct bprm_security_struct *bsec; @@ -1643,15 +1660,16 @@ static int selinux_bprm_set_security(struct linux_binprm *bprm) return 0; tsec = current->security; + csec = bprm->cred->security; isec = inode->i_security; /* Default to the current task SID. */ - bsec->sid = tsec->sid; + bsec->sid = csec->action_sid; /* Reset fs, key, and sock SIDs on execve. */ - tsec->create_sid = 0; - tsec->keycreate_sid = 0; - tsec->sockcreate_sid = 0; + csec->create_sid = 0; + csec->keycreate_sid = 0; + csec->sockcreate_sid = 0; if (tsec->exec_sid) { newsid = tsec->exec_sid; @@ -1659,7 +1677,7 @@ static int selinux_bprm_set_security(struct linux_binprm *bprm) tsec->exec_sid = 0; } else { /* Check for a default transition on this program. */ - rc = security_transition_sid(tsec->sid, isec->sid, + rc = security_transition_sid(csec->action_sid, isec->sid, SECCLASS_PROCESS, &newsid); if (rc) return rc; @@ -1670,16 +1688,16 @@ static int selinux_bprm_set_security(struct linux_binprm *bprm) ad.u.fs.dentry = bprm->file->f_path.dentry; if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) - newsid = tsec->sid; + newsid = csec->action_sid; - if (tsec->sid == newsid) { - rc = avc_has_perm(tsec->sid, isec->sid, + if (csec->action_sid == newsid) { + rc = avc_has_perm(csec->action_sid, isec->sid, SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); if (rc) return rc; } else { /* Check permissions for the transition. */ - rc = avc_has_perm(tsec->sid, newsid, + rc = avc_has_perm(csec->action_sid, newsid, SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); if (rc) return rc; @@ -1711,11 +1729,11 @@ static int selinux_bprm_secureexec (struct linux_binprm *bprm) struct task_security_struct *tsec = current->security; int atsecure = 0; - if (tsec->osid != tsec->sid) { + if (tsec->osid != tsec->victim_sid) { /* Enable secure mode for SIDs transitions unless the noatsecure permission is granted between the two SIDs, i.e. ahp returns 0. */ - atsecure = avc_has_perm(tsec->osid, tsec->sid, + atsecure = avc_has_perm(tsec->osid, tsec->victim_sid, SECCLASS_PROCESS, PROCESS__NOATSECURE, NULL); } @@ -1825,6 +1843,7 @@ static inline void flush_unauthorized_files(struct files_struct * files) static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) { struct task_security_struct *tsec; + struct cred_security_struct *csec; struct bprm_security_struct *bsec; u32 sid; int rc; @@ -1832,17 +1851,17 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) secondary_ops->bprm_apply_creds(bprm, unsafe); tsec = current->security; - + csec = bprm->cred->security; bsec = bprm->security; sid = bsec->sid; - tsec->osid = tsec->sid; + tsec->osid = tsec->victim_sid; bsec->unsafe = 0; - if (tsec->sid != sid) { + if (tsec->victim_sid != sid) { /* Check for shared state. If not ok, leave SID unchanged and kill. */ if (unsafe & LSM_UNSAFE_SHARE) { - rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, + rc = avc_has_perm(tsec->victim_sid, sid, SECCLASS_PROCESS, PROCESS__SHARE, NULL); if (rc) { bsec->unsafe = 1; @@ -1861,7 +1880,9 @@ static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe) return; } } - tsec->sid = sid; + if (csec->action_sid == tsec->victim_sid) + csec->action_sid = sid; + tsec->victim_sid = sid; } } @@ -1883,7 +1904,7 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) force_sig_specific(SIGKILL, current); return; } - if (tsec->osid == tsec->sid) + if (tsec->osid == tsec->victim_sid) return; /* Close files for which the new task SID is not authorized. */ @@ -1895,7 +1916,7 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) signals. This must occur _after_ the task SID has been updated so that any kill done after the flush will be checked against the new SID. */ - rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS, + rc = avc_has_perm(tsec->osid, tsec->victim_sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); if (rc) { memset(&itimer, 0, sizeof itimer); @@ -1922,7 +1943,7 @@ static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm) than the default soft limit for cases where the default is lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.*/ - rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS, + rc = avc_has_perm(tsec->osid, tsec->victim_sid, SECCLASS_PROCESS, PROCESS__RLIMITINH, NULL); if (rc) { for (i = 0; i < RLIM_NLIMITS; i++) { @@ -2124,21 +2145,21 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir, char **name, void **value, size_t *len) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct inode_security_struct *dsec; struct superblock_security_struct *sbsec; u32 newsid, clen; int rc; char *namep = NULL, *context; - tsec = current->security; + csec = current->cred->security; dsec = dir->i_security; sbsec = dir->i_sb->s_security; - if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { - newsid = tsec->create_sid; + if (csec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { + newsid = csec->create_sid; } else { - rc = security_transition_sid(tsec->sid, dsec->sid, + rc = security_transition_sid(csec->action_sid, dsec->sid, inode_mode_to_security_class(inode->i_mode), &newsid); if (rc) { @@ -2297,7 +2318,7 @@ static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags) { - struct task_security_struct *tsec = current->security; + struct cred_security_struct *csec = current->cred->security; struct inode *inode = dentry->d_inode; struct inode_security_struct *isec = inode->i_security; struct superblock_security_struct *sbsec; @@ -2329,7 +2350,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value AVC_AUDIT_DATA_INIT(&ad,FS); ad.u.fs.dentry = dentry; - rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, + rc = avc_has_perm(csec->action_sid, isec->sid, isec->sclass, FILE__RELABELFROM, &ad); if (rc) return rc; @@ -2338,12 +2359,12 @@ static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value if (rc) return rc; - rc = avc_has_perm(tsec->sid, newsid, isec->sclass, + rc = avc_has_perm(csec->action_sid, newsid, isec->sclass, FILE__RELABELTO, &ad); if (rc) return rc; - rc = security_validate_transition(isec->sid, newsid, tsec->sid, + rc = security_validate_transition(isec->sid, newsid, csec->action_sid, isec->sclass); if (rc) return rc; @@ -2577,8 +2598,9 @@ static int selinux_file_mmap(struct file *file, unsigned long reqprot, unsigned long prot, unsigned long flags, unsigned long addr, unsigned long addr_only) { + struct cred_security_struct *csec = current->cred->security; int rc = 0; - u32 sid = ((struct task_security_struct*)(current->security))->sid; + u32 sid = csec->action_sid; if (addr < mmap_min_addr) rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, @@ -2692,7 +2714,7 @@ static int selinux_file_set_fowner(struct file *file) tsec = current->security; fsec = file->f_security; - fsec->fown_sid = tsec->sid; + fsec->fown_sid = tsec->victim_sid; return 0; } @@ -2716,7 +2738,7 @@ static int selinux_file_send_sigiotask(struct task_struct *tsk, else perm = signal_to_av(signum); - return avc_has_perm(fsec->fown_sid, tsec->sid, + return avc_has_perm(fsec->fown_sid, tsec->victim_sid, SECCLASS_PROCESS, perm, NULL); } @@ -2725,6 +2747,31 @@ static int selinux_file_receive(struct file *file) return file_has_perm(current, file, file_to_av(file)); } +/* credential security operations */ + +/* + * duplicate the security information attached to a credentials record that is + * itself undergoing duplication + */ +static int selinux_cred_dup(struct cred *cred) +{ + cred->security = kmemdup(cred->security, + sizeof(struct cred_security_struct), + GFP_KERNEL); + return cred->security ? 0 : -ENOMEM; +} + +/* + * destroy the security information attached to a credentials record + * - this is done under RCU, and may not be associated with the task that set it + * up + */ +static void selinux_cred_destroy(struct cred *cred) +{ + kfree(cred->security); +} + + /* task security operations */ static int selinux_task_create(unsigned long clone_flags) @@ -2751,13 +2798,10 @@ static int selinux_task_alloc_security(struct task_struct *tsk) tsec2 = tsk->security; tsec2->osid = tsec1->osid; - tsec2->sid = tsec1->sid; + tsec2->victim_sid = tsec1->victim_sid; - /* Retain the exec, fs, key, and sock SIDs across fork */ + /* Retain the exec SID across fork */ tsec2->exec_sid = tsec1->exec_sid; - tsec2->create_sid = tsec1->create_sid; - tsec2->keycreate_sid = tsec1->keycreate_sid; - tsec2->sockcreate_sid = tsec1->sockcreate_sid; /* Retain ptracer SID across fork, if any. This will be reset by the ptrace hook upon any @@ -2895,7 +2939,8 @@ static int selinux_task_kill(struct task_struct *p, struct siginfo *info, perm = signal_to_av(sig); tsec = p->security; if (secid) - rc = avc_has_perm(secid, tsec->sid, SECCLASS_PROCESS, perm, NULL); + rc = avc_has_perm(secid, tsec->victim_sid, + SECCLASS_PROCESS, perm, NULL); else rc = task_has_perm(current, p, perm); return rc; @@ -2929,8 +2974,8 @@ static void selinux_task_reparent_to_init(struct task_struct *p) secondary_ops->task_reparent_to_init(p); tsec = p->security; - tsec->osid = tsec->sid; - tsec->sid = SECINITSID_KERNEL; + tsec->osid = tsec->victim_sid; + tsec->victim_sid = SECINITSID_KERNEL; return; } @@ -2940,7 +2985,7 @@ static void selinux_task_to_inode(struct task_struct *p, struct task_security_struct *tsec = p->security; struct inode_security_struct *isec = inode->i_security; - isec->sid = tsec->sid; + isec->sid = tsec->victim_sid; isec->initialized = 1; return; } @@ -3165,11 +3210,11 @@ static int socket_has_perm(struct task_struct *task, struct socket *sock, u32 perms) { struct inode_security_struct *isec; - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct avc_audit_data ad; int err = 0; - tsec = task->security; + csec = task->cred->security; isec = SOCK_INODE(sock)->i_security; if (isec->sid == SECINITSID_KERNEL) @@ -3177,7 +3222,8 @@ static int socket_has_perm(struct task_struct *task, struct socket *sock, AVC_AUDIT_DATA_INIT(&ad,NET); ad.u.net.sk = sock->sk; - err = avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad); + err = avc_has_perm(csec->action_sid, isec->sid, isec->sclass, perms, + &ad); out: return err; @@ -3187,15 +3233,15 @@ static int selinux_socket_create(int family, int type, int protocol, int kern) { int err = 0; - struct task_security_struct *tsec; + struct cred_security_struct *csec; u32 newsid; if (kern) goto out; - tsec = current->security; - newsid = tsec->sockcreate_sid ? : tsec->sid; - err = avc_has_perm(tsec->sid, newsid, + csec = current->cred->security; + newsid = csec->sockcreate_sid ? : csec->action_sid; + err = avc_has_perm(csec->action_sid, newsid, socket_type_to_security_class(family, type, protocol), SOCKET__CREATE, NULL); @@ -3208,14 +3254,14 @@ static int selinux_socket_post_create(struct socket *sock, int family, { int err = 0; struct inode_security_struct *isec; - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct sk_security_struct *sksec; u32 newsid; isec = SOCK_INODE(sock)->i_security; - tsec = current->security; - newsid = tsec->sockcreate_sid ? : tsec->sid; + csec = current->cred->security; + newsid = csec->sockcreate_sid ? : csec->action_sid; isec->sclass = socket_type_to_security_class(family, type, protocol); isec->sid = kern ? SECINITSID_KERNEL : newsid; isec->initialized = 1; @@ -4029,7 +4075,7 @@ static int ipc_alloc_security(struct task_struct *task, struct kern_ipc_perm *perm, u16 sclass) { - struct task_security_struct *tsec = task->security; + struct cred_security_struct *csec = task->cred->security; struct ipc_security_struct *isec; isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); @@ -4038,7 +4084,7 @@ static int ipc_alloc_security(struct task_struct *task, isec->sclass = sclass; isec->ipc_perm = perm; - isec->sid = tsec->sid; + isec->sid = csec->action_sid; perm->security = isec; return 0; @@ -4077,17 +4123,18 @@ static void msg_msg_free_security(struct msg_msg *msg) static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, u32 perms) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + csec = current->cred->security; isec = ipc_perms->security; AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = ipc_perms->key; - return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad); + return avc_has_perm(csec->action_sid, isec->sid, isec->sclass, perms, + &ad); } static int selinux_msg_msg_alloc_security(struct msg_msg *msg) @@ -4103,7 +4150,7 @@ static void selinux_msg_msg_free_security(struct msg_msg *msg) /* message queue security operations */ static int selinux_msg_queue_alloc_security(struct msg_queue *msq) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct avc_audit_data ad; int rc; @@ -4112,13 +4159,13 @@ static int selinux_msg_queue_alloc_security(struct msg_queue *msq) if (rc) return rc; - tsec = current->security; + csec = current->cred->security; isec = msq->q_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = msq->q_perm.key; - rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ, + rc = avc_has_perm(csec->action_sid, isec->sid, SECCLASS_MSGQ, MSGQ__CREATE, &ad); if (rc) { ipc_free_security(&msq->q_perm); @@ -4134,17 +4181,17 @@ static void selinux_msg_queue_free_security(struct msg_queue *msq) static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + csec = current->cred->security; isec = msq->q_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = msq->q_perm.key; - return avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ, + return avc_has_perm(csec->action_sid, isec->sid, SECCLASS_MSGQ, MSGQ__ASSOCIATE, &ad); } @@ -4178,13 +4225,13 @@ static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd) static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct msg_security_struct *msec; struct avc_audit_data ad; int rc; - tsec = current->security; + csec = current->cred->security; isec = msq->q_perm.security; msec = msg->security; @@ -4196,7 +4243,7 @@ static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, * Compute new sid based on current process and * message queue this message will be stored in */ - rc = security_transition_sid(tsec->sid, + rc = security_transition_sid(csec->action_sid, isec->sid, SECCLASS_MSG, &msec->sid); @@ -4208,11 +4255,11 @@ static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, ad.u.ipc_id = msq->q_perm.key; /* Can this process write to the queue? */ - rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ, + rc = avc_has_perm(csec->action_sid, isec->sid, SECCLASS_MSGQ, MSGQ__WRITE, &ad); if (!rc) /* Can this process send the message */ - rc = avc_has_perm(tsec->sid, msec->sid, + rc = avc_has_perm(csec->action_sid, msec->sid, SECCLASS_MSG, MSG__SEND, &ad); if (!rc) /* Can the message be put in the queue? */ @@ -4239,10 +4286,10 @@ static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = msq->q_perm.key; - rc = avc_has_perm(tsec->sid, isec->sid, + rc = avc_has_perm(tsec->victim_sid, isec->sid, SECCLASS_MSGQ, MSGQ__READ, &ad); if (!rc) - rc = avc_has_perm(tsec->sid, msec->sid, + rc = avc_has_perm(tsec->victim_sid, msec->sid, SECCLASS_MSG, MSG__RECEIVE, &ad); return rc; } @@ -4250,7 +4297,7 @@ static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, /* Shared Memory security operations */ static int selinux_shm_alloc_security(struct shmid_kernel *shp) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct avc_audit_data ad; int rc; @@ -4259,13 +4306,13 @@ static int selinux_shm_alloc_security(struct shmid_kernel *shp) if (rc) return rc; - tsec = current->security; + csec = current->cred->security; isec = shp->shm_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = shp->shm_perm.key; - rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM, + rc = avc_has_perm(csec->action_sid, isec->sid, SECCLASS_SHM, SHM__CREATE, &ad); if (rc) { ipc_free_security(&shp->shm_perm); @@ -4281,17 +4328,17 @@ static void selinux_shm_free_security(struct shmid_kernel *shp) static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + csec = current->cred->security; isec = shp->shm_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = shp->shm_perm.key; - return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM, + return avc_has_perm(csec->action_sid, isec->sid, SECCLASS_SHM, SHM__ASSOCIATE, &ad); } @@ -4349,7 +4396,7 @@ static int selinux_shm_shmat(struct shmid_kernel *shp, /* Semaphore security operations */ static int selinux_sem_alloc_security(struct sem_array *sma) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct avc_audit_data ad; int rc; @@ -4358,13 +4405,13 @@ static int selinux_sem_alloc_security(struct sem_array *sma) if (rc) return rc; - tsec = current->security; + csec = current->cred->security; isec = sma->sem_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = sma->sem_perm.key; - rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM, + rc = avc_has_perm(csec->action_sid, isec->sid, SECCLASS_SEM, SEM__CREATE, &ad); if (rc) { ipc_free_security(&sma->sem_perm); @@ -4380,17 +4427,17 @@ static void selinux_sem_free_security(struct sem_array *sma) static int selinux_sem_associate(struct sem_array *sma, int semflg) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct ipc_security_struct *isec; struct avc_audit_data ad; - tsec = current->security; + csec = current->cred->security; isec = sma->sem_perm.security; AVC_AUDIT_DATA_INIT(&ad, IPC); ad.u.ipc_id = sma->sem_perm.key; - return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM, + return avc_has_perm(csec->action_sid, isec->sid, SECCLASS_SEM, SEM__ASSOCIATE, &ad); } @@ -4506,6 +4553,7 @@ static int selinux_getprocattr(struct task_struct *p, char *name, char **value) { struct task_security_struct *tsec; + struct cred_security_struct *csec; u32 sid; int error; unsigned len; @@ -4517,22 +4565,25 @@ static int selinux_getprocattr(struct task_struct *p, } tsec = p->security; + rcu_read_lock(); + csec = task_cred(p)->security; if (!strcmp(name, "current")) - sid = tsec->sid; + sid = tsec->victim_sid; else if (!strcmp(name, "prev")) sid = tsec->osid; else if (!strcmp(name, "exec")) sid = tsec->exec_sid; else if (!strcmp(name, "fscreate")) - sid = tsec->create_sid; + sid = csec->create_sid; else if (!strcmp(name, "keycreate")) - sid = tsec->keycreate_sid; + sid = csec->keycreate_sid; else if (!strcmp(name, "sockcreate")) - sid = tsec->sockcreate_sid; + sid = csec->sockcreate_sid; else - return -EINVAL; + goto invalid; + rcu_read_unlock(); if (!sid) return 0; @@ -4540,13 +4591,20 @@ static int selinux_getprocattr(struct task_struct *p, if (error) return error; return len; + +invalid: + rcu_read_unlock(); + return -EINVAL; } static int selinux_setprocattr(struct task_struct *p, char *name, void *value, size_t size) { struct task_security_struct *tsec; - u32 sid = 0; + struct cred_security_struct *csec; + struct av_decision avd; + struct cred *cred; + u32 sid = 0, perm; int error; char *str = value; @@ -4562,17 +4620,19 @@ static int selinux_setprocattr(struct task_struct *p, * above restriction is ever removed. */ if (!strcmp(name, "exec")) - error = task_has_perm(current, p, PROCESS__SETEXEC); + perm = PROCESS__SETEXEC; else if (!strcmp(name, "fscreate")) - error = task_has_perm(current, p, PROCESS__SETFSCREATE); + perm = PROCESS__SETFSCREATE; else if (!strcmp(name, "keycreate")) - error = task_has_perm(current, p, PROCESS__SETKEYCREATE); + perm = PROCESS__SETKEYCREATE; else if (!strcmp(name, "sockcreate")) - error = task_has_perm(current, p, PROCESS__SETSOCKCREATE); + perm = PROCESS__SETSOCKCREATE; else if (!strcmp(name, "current")) - error = task_has_perm(current, p, PROCESS__SETCURRENT); + perm = PROCESS__SETCURRENT; else - error = -EINVAL; + return -EINVAL; + + error = task_has_perm(current, p, perm); if (error) return error; @@ -4594,20 +4654,37 @@ static int selinux_setprocattr(struct task_struct *p, checks and may_create for the file creation checks. The operation will then fail if the context is not permitted. */ tsec = p->security; - if (!strcmp(name, "exec")) + csec = p->cred->security; + switch (perm) { + case PROCESS__SETEXEC: tsec->exec_sid = sid; - else if (!strcmp(name, "fscreate")) - tsec->create_sid = sid; - else if (!strcmp(name, "keycreate")) { + break; + + case PROCESS__SETKEYCREATE: error = may_create_key(sid, p); if (error) return error; - tsec->keycreate_sid = sid; - } else if (!strcmp(name, "sockcreate")) - tsec->sockcreate_sid = sid; - else if (!strcmp(name, "current")) { - struct av_decision avd; + case PROCESS__SETFSCREATE: + case PROCESS__SETSOCKCREATE: + cred = dup_cred(current->cred); + if (!cred) + return -ENOMEM; + csec = cred->security; + switch (perm) { + case PROCESS__SETKEYCREATE: + csec->keycreate_sid = sid; + break; + case PROCESS__SETFSCREATE: + csec->create_sid = sid; + break; + case PROCESS__SETSOCKCREATE: + csec->sockcreate_sid = sid; + break; + } + set_current_cred(cred); + break; + case PROCESS__SETCURRENT: if (sid == 0) return -EINVAL; @@ -4626,11 +4703,16 @@ static int selinux_setprocattr(struct task_struct *p, } /* Check permissions for the transition. */ - error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, + error = avc_has_perm(csec->action_sid, sid, SECCLASS_PROCESS, PROCESS__DYNTRANSITION, NULL); if (error) return error; + cred = dup_cred(current->cred); + if (!cred) + return -ENOMEM; + csec = cred->security; + /* Check for ptracing, and update the task SID if ok. Otherwise, leave SID unchanged and fail. */ task_lock(p); @@ -4638,20 +4720,25 @@ static int selinux_setprocattr(struct task_struct *p, error = avc_has_perm_noaudit(tsec->ptrace_sid, sid, SECCLASS_PROCESS, PROCESS__PTRACE, 0, &avd); - if (!error) - tsec->sid = sid; + if (!error) { + csec->action_sid = tsec->victim_sid = sid; + } task_unlock(p); avc_audit(tsec->ptrace_sid, sid, SECCLASS_PROCESS, PROCESS__PTRACE, &avd, error, NULL); - if (error) + if (error) { + put_cred(cred); return error; + } } else { - tsec->sid = sid; + csec->action_sid = tsec->victim_sid = sid; task_unlock(p); } - } - else + set_current_cred(cred); + break; + default: return -EINVAL; + } return size; } @@ -4671,18 +4758,21 @@ static void selinux_release_secctx(char *secdata, u32 seclen) static int selinux_key_alloc(struct key *k, struct task_struct *tsk, unsigned long flags) { - struct task_security_struct *tsec = tsk->security; + struct cred_security_struct *csec; struct key_security_struct *ksec; ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); if (!ksec) return -ENOMEM; + rcu_read_lock(); + csec = task_cred(tsk)->security; ksec->obj = k; - if (tsec->keycreate_sid) - ksec->sid = tsec->keycreate_sid; + if (csec->keycreate_sid) + ksec->sid = csec->keycreate_sid; else - ksec->sid = tsec->sid; + ksec->sid = csec->action_sid; + rcu_read_unlock(); k->security = ksec; return 0; @@ -4697,17 +4787,13 @@ static void selinux_key_free(struct key *k) } static int selinux_key_permission(key_ref_t key_ref, - struct task_struct *ctx, - key_perm_t perm) + struct task_struct *ctx, + key_perm_t perm) { struct key *key; - struct task_security_struct *tsec; + struct cred_security_struct *csec; struct key_security_struct *ksec; - - key = key_ref_to_ptr(key_ref); - - tsec = ctx->security; - ksec = key->security; + u32 action_sid; /* if no specific permissions are requested, we skip the permission check. No serious, additional covert channels @@ -4715,7 +4801,16 @@ static int selinux_key_permission(key_ref_t key_ref, if (perm == 0) return 0; - return avc_has_perm(tsec->sid, ksec->sid, + key = key_ref_to_ptr(key_ref); + + rcu_read_lock(); + csec = task_cred(ctx)->security; + action_sid = csec->action_sid; + rcu_read_unlock(); + + ksec = key->security; + + return avc_has_perm(action_sid, ksec->sid, SECCLASS_KEY, perm, NULL); } @@ -4790,6 +4885,9 @@ static struct security_operations selinux_ops = { .file_send_sigiotask = selinux_file_send_sigiotask, .file_receive = selinux_file_receive, + .cred_dup = selinux_cred_dup, + .cred_destroy = selinux_cred_destroy, + .task_create = selinux_task_create, .task_alloc_security = selinux_task_alloc_security, .task_free_security = selinux_task_free_security, @@ -4898,6 +4996,17 @@ static struct security_operations selinux_ops = { #endif }; +/* + * initial security credentials + * - attached to init_cred which is never released + */ +static struct cred_security_struct init_cred_sec = { + .action_sid = SECINITSID_KERNEL, + .create_sid = SECINITSID_UNLABELED, + .keycreate_sid = SECINITSID_UNLABELED, + .sockcreate_sid = SECINITSID_UNLABELED, +}; + static __init int selinux_init(void) { struct task_security_struct *tsec; @@ -4909,11 +5018,15 @@ static __init int selinux_init(void) printk(KERN_INFO "SELinux: Initializing.\n"); + /* Set the security state for the initial credentials */ + init_cred.security = &init_cred_sec; + BUG_ON(current->cred != &init_cred); + /* Set the security state for the initial task. */ if (task_alloc_security(current)) panic("SELinux: Failed to initialize initial task.\n"); tsec = current->security; - tsec->osid = tsec->sid = SECINITSID_KERNEL; + tsec->osid = tsec->victim_sid = SECINITSID_KERNEL; sel_inode_cache = kmem_cache_create("selinux_inode_security", sizeof(struct inode_security_struct), diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 91b88f0..a1dbc1c 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -27,14 +27,22 @@ #include "flask.h" #include "avc.h" +/* + * the security parameters associated with the credentials record structure + * (struct cred::security) + */ +struct cred_security_struct { + u32 action_sid; /* perform action as SID */ + u32 create_sid; /* filesystem object creation as SID */ + u32 keycreate_sid; /* key creation as SID */ + u32 sockcreate_sid; /* socket creation as SID */ +}; + struct task_security_struct { struct task_struct *task; /* back pointer to task object */ u32 osid; /* SID prior to last execve */ - u32 sid; /* current SID */ + u32 victim_sid; /* current SID affecting victimisation of this task */ u32 exec_sid; /* exec SID */ - u32 create_sid; /* fscreate SID */ - u32 keycreate_sid; /* keycreate SID */ - u32 sockcreate_sid; /* fscreate SID */ u32 ptrace_sid; /* SID of ptrace parent */ }; diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index c9e92da..9c6737f 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -77,13 +77,13 @@ extern void selnl_notify_setenforce(int val); static int task_has_security(struct task_struct *tsk, u32 perms) { - struct task_security_struct *tsec; + struct cred_security_struct *csec; - tsec = tsk->security; - if (!tsec) + csec = tsk->cred->security; + if (!csec) return -EACCES; - return avc_has_perm(tsec->sid, SECINITSID_SECURITY, + return avc_has_perm(csec->action_sid, SECINITSID_SECURITY, SECCLASS_SECURITY, perms, NULL); } diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c index ba715f4..902d302 100644 --- a/security/selinux/xfrm.c +++ b/security/selinux/xfrm.c @@ -240,7 +240,7 @@ static int selinux_xfrm_sec_ctx_alloc(struct xfrm_sec_ctx **ctxp, /* * Does the subject have permission to set security context? */ - rc = avc_has_perm(tsec->sid, ctx->ctx_sid, + rc = avc_has_perm(tsec->action_sid, ctx->ctx_sid, SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL); if (rc) @@ -341,7 +341,7 @@ int selinux_xfrm_policy_delete(struct xfrm_policy *xp) int rc = 0; if (ctx) - rc = avc_has_perm(tsec->sid, ctx->ctx_sid, + rc = avc_has_perm(tsec->action_sid, ctx->ctx_sid, SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL); @@ -383,7 +383,7 @@ int selinux_xfrm_state_delete(struct xfrm_state *x) int rc = 0; if (ctx) - rc = avc_has_perm(tsec->sid, ctx->ctx_sid, + rc = avc_has_perm(tsec->action_sid, ctx->ctx_sid, SECCLASS_ASSOCIATION, ASSOCIATION__SETCONTEXT, NULL); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/